The present invention relates to a carrier system for fragrances, to the production thereof and to the use of the carrier system in various fields of industry.
For protection of valuable chemical compounds such as dyes, medicaments and crop protection compositions, enzymes, but also fragrances or odorants, during storage before intended use, the use of microcapsules is increasingly being considered or is already being practiced. These microcapsules enable the valuable active ingredient to be provided already distributed relatively homogeneously in a use mixture, without having to expose it to the other constituents during storage. Suitable selection of the shell of the capsule also allows effects included retarded release to be achieved in this way.
For example, EP 0 457 154 describes a shell of polymer, more specifically of 30 to 100% by mass of alkyl ester of acrylic acid or methacrylic acid and 0 to 80% by mass of a bi- or polyfunctional monomer, and also 0 to 40% by mass of other vinylic monomers, for encapsulation of color carriers. These color carriers are notable for low volatility.
WO 05/105291 discloses a shell of polymer composed of 5 to 90% by mass of water-soluble monomers such as acrylic acid or methacrylic acid, 5 to 90% by mass of a bi- or polyfunctional monomer and 0 to 55% by mass of low water solubility monomers such as alkyl esters of acrylic acid or methacrylic acid. It serves for encapsulation of paraffins, i.e. likewise of nonvolatile substances, for coating of textiles directly in the spinning process.
WO 08/058,868 too, which discloses a shell of a polymer composed of 1 to 95% by mass of water-soluble monomers such as acrylic acid or methacrylic acid, 5 to 99% by mass of a bi- or polyfunctional monomer and 0 to 60% by mass of low water solubility monomers such as alkyl esters of acrylic acid or methacrylic acid, serves to enclose a nonvolatile substance, namely a paraffin.
For use of microcapsules for preserving volatile chemical compounds, which include, for example, many fragrances or odorants, for applications in washing and cleaning compositions and for laundry and surface treatment, the capsules must enclose the volatile substance particularly efficiently. It was therefore an object of the present invention to provide a microcapsule with improved imperviosity for volatile substances.
The object is surprisingly achieved by the microcapsules according to claims 1 to 7; a chemical composition comprising them according to claims 8 and 9, and also the uses according to claims 10 to 13 and the articles comprising microparticles according to claims 14 and 15 form further constituent parts of the present invention.